High‐pressure Raman study of CsVO3 and pressure‐induced phase transitions
High‐pressure Raman study of CsVO3 and pressure‐induced phase transitions
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DOI：
10.1002/jrs.1250220203
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发表时间：
1991-02
影响因子：
2.5
通讯作者：
G. Kourouklis;A. Jayaraman;G. Espinosa;A. S. Cooper
中科院分区：
文献类型：
--
作者：
G. Kourouklis;A. Jayaraman;G. Espinosa;A. S. Cooper
利用金刚石对顶砧装置研究了钒酸铯（CsVO 3）的拉曼频率随压力的变化关系，压力高达15 GPa。从拉曼光谱的突变推断三个压力诱导相变在10，11.5和13 GPa。第一个相变，在10 GPa，是微妙的，但影响VO键长。据信，这种转变与在钒酸钾和钒酸铷中观察到的性质相同。CsVO3的相变压力高得多是由于Cs+离子的反常压缩性。第二相变涉及高频区域中更剧烈的变化。这是由于VO4四面体的旋转和扭曲降低了晶格的对称性。在第三个相变中，较宽的拉曼峰的出现和链变形模式的消失表明链结构中的部分无序。
The pressure dependence of the Raman frequencies of cesium vanadate (CsVO3) was studied using a diamond anvil cell up to 15 GPa. From the abrupt changes in the Raman specta three pressure-induced phase transitions are inferred at 10, 11.5 and 13 GPa. The first phase transition, at 10 GPa, is subtle but affects the VO bond length. It is believed that this transition is of the same nature as that observed in postassium and rubidium vanadates. The much higher transformation pressure in CsVO3 is attributed to the anomalous compressibility of the Cs+ ion. The second phase transition involves more drastic changes in the high-frequency region. This is attributed to the rotations and distortions in the VO4 tetrahedra which lower the symmetry of the lattice. In the third phase transition, the appearance of broader Raman peaks and the disappearance of the chain deformation modes suggest a partial disorder in the chain structure.